He studied law, and was admitted to the bar association and commenced practice in Salem, Massachusetts, in 1805.

Salem City Hall was built in 1837–1838 under the supervision of Mayor Leverett Saltonstall and a committee appointed for that purpose.

Artifacts buried beneath the cornerstone included copies of local newspapers, the Mayor's speech for the organization of City Government (May 9, 1836), and the new City Charter.

Saltonstall, his brother-in-law Dudley Leavitt Pickman and Nathaniel Bowditch all acted as trustees of the estate of Simon Forrester, a ship captain born in Ireland who became one of pioneers of Salem merchant shipping and one of Salem's leading merchants and philanthropists.

[8][9] Leverett Saltonstall died in Salem, Essex County, Massachusetts, May 8, 1845, and rests in Harmony Grove Cemetery.